The present invention relates to water disinfecting systems, and more particularly, to an apparatus for generating disinfecting solutions to be added to potentially contaminated water to render that water potable.
Maintaining the sterility of drinking water supplies is a major factor in reducing the health risks to human populations. While large metropolitan water systems can make use of highly toxic chlorine gas for sterilizing drinking water, such systems are impractical in remote locations, which lack highly trained personnel and the equipment to maintain the systems. There are many settings in which sophisticated systems are not practical. For example, campers or military personnel in the field cannot be expected to operate such a system to provide potable drinking water from streams or other potentially contaminated water sources. To be effective in such rural settings, a system must be capable of running for long periods of time with little or no maintenance. In addition, the raw materials required by the system must be readily available.
Systems based on the electrolytic production of chlorine and/or other chlor-oxygen species based germicidal agents are particularly attractive for use in the present invention. These systems require only electricity and common salt as raw materials. One such system is described in U.S. Pat. No. 4,761,208 to Gram, et al. entitled Electrolytic Method and Cell for Sterilizing Water, which is incorporated herein by reference. The system of the present invention utilizes an electrolytic cell to generate an oxidant solution including chlorine in the form of hypochlorous acid and other chlor-oxygen species. Other embodiments of the present invention produce an oxidant solution that is predominantly sodium hypochlorite. The oxidant solution is produced from a brine solution using common salt. This oxidant solution may be added directly to the drinking water at a dilution ratio compatible with the concentration of the oxidant produced in the device and the demand of the water. The oxidant produced is more effective at inactivation of microorganisms than is conventional chlorination technology, including chlorine gas, sodium hypochlorite, and calcium hypochlorite. At adequate dilution ratios, the water is sterilized without causing the water to become unpalatable. This technology is particularly attractive because of its simplicity and long maintenance free operation time. Studies have been conducted to demonstrate the microorganism inactivation effectiveness of the oxidant, commonly referred to as mixed-oxidant solution. Linda V. Venczel, Michael Arrowood, Margaret Hurd, and Mark D. Sobsey with the University of North Carolina at Chapel Hill, N.C. have conducted research and published a paper entitled, Inactivation of Cryptosporidium parvum Oocysts and Clostridium perfringens Spores by a Mixed-Oxidant Disinfectant and by Free Chlorine, published in Applied and Environmental Microbiology, April 1997, p. 1598-1601.
The systems based on mixed-oxidant production have been used successfully in rural communities with small water supplies to larger municipal water systems treating millions of gallons per day. These larger systems are not well suited for use by individual campers and personnel in the field who must treat small quantities of water on a daily basis. The mixed oxidant systems designed to date are applicable to large quantities of water and are large and heavy. In addition, these systems require quantities of electrical power that are not practical at the mesoscale, or individual person level.
The present invention comprises a portable oxidant generator comprising at least one cell wherein the cell comprises at least two electrodes wherein at least one electrode comprises at least one cathode and at least one anode. In a preferred embodiment, the oxidant generator comprises a circuit for providing an electrical potential between at least one of the at least one cathode and at least one of the at least one anode. In such an embodiment, the circuit comprises electricity that originates from an energy source, such as, but not limited to, energy sources comprising mechanical sources, chemical sources, magnetic sources, pressure sources and/or electromagnetic radiation sources. In a preferred embodiment, oxidant generation relies on an electrolyte solution that is placed in a cell wherein an applied electrical potential causes electrical charge to pass to the electrolyte solution thereby generating at least one oxidant in the electrolyte solution. According to the present invention, electrolyte and/or electrolyte solution resides in a cell that generates oxidant in a batch mode and/or electrolyte and/or electrolyte solution passes through a cell that generates oxidant in a continuous mode. In a preferred embodiment, an electrolyte solution resides in a cell that generates oxidant in a batch mode. In such a preferred embodiment, individual aliquots of batch mode generated oxidants are added to a liquid in an effort to disinfect the liquid. Of course, oxidants generated by the apparatus and method of the present invention are suitable for disinfecting, bleaching and/or degrading liquid as well as other material, such as, but not limited to, human and/or animal body parts and food and material contained in a liquid. Oxidants generally comprise chemically reactive species capable of oxidizing a substance by, for example, accepting electrons. Therefore, the oxidants generated by the apparatus of the present invention comprise many uses.
In a preferred embodiment, the portable generator comprises an annular cell comprising an inner annular surface and an outer annular surface. In a preferred embodiment, the annular cell comprises at least one electrode positioned on the inner annular surface and/or at least one electrode positioned on the outer annular surface. Such electrodes optionally comprise the surface and/or electrodes in contact with the surface, for example, pins and/or plates. In a preferred embodiment, the at least one of the at least two electrodes comprises at least one catalyst. For example, in embodiments comprising a catalyst, a catalyst optionally comprises at least one Group VIIIB element of the Periodic Table of Elements and/or compounds thereof and preferably, at least one catalyst comprises ruthenium oxide.
According to the present invention, an electrical charge is delivered to a solution and/or substance comprising, for example, electrolyte. In a preferred embodiment, the circuit delivers a controlled electrical charge to an electrolyte solution. In an alternative embodiment, the oxidant generating apparatus measures and/or signals a characteristic of oxidant generation that terminates electrical charge delivery and/or notifies a user to terminate electrical charge delivery. In a preferred embodiment, the portable oxidant generator comprises a circuit that measures the electrical charge passed to an electrolyte solution and/or other electrolytic substance, for example, but not limited to, a gel and/or a solid.
In a preferred embodiment, the portable generator further comprises an output device for outputting information. For example, an output device for outputting information optionally comprises at least one output such as tactile, auditory, olfactory and visual outputs. Alternatively, the output comprises an electromagnetic output comprising, for example, electromagnetic radiation. According to a preferred embodiment of the present invention, information comprises at least one type of information selected from the group consisting of electrical charge, energy level, remaining energy, electrolyte level, remaining electrolyte, integrity of said portable generator, temperature, total dissolved solids, conductivity, pH, ion concentration, residual oxidant, and oxidation-reduction potential. The generator of the present invention optionally comprises a circuit for measuring at least one condition selected from the group consisting of temperature, total dissolved solids, conductivity, pH, ion concentration, residual oxidant, and oxidation-reduction potential. Such information is optionally provided to the same and/or a different circuit for providing at least one electrical potential for oxidant generation and/or other use.
In a preferred embodiment, the cell of the inventive generator comprises a reservoir, for example, but not limited to, a reservoir for holding a batch for batch mode operation. The generator optionally comprises at least one reservoir, which optionally comprises the cell, an additional cell, and/or a reservoir other than a cell. In embodiments comprising at least one reservoir, the reservoir optionally comprises an electrolyte reservoir, for example, but not limited to, a salt reservoir, a refillable reservoir, a disposable reservoir, and/or a self-sealing reservoir wherein the self-sealing reservoir optionally comprises a seal selected from the group consisting of an elastomer and a mechanical check valve.
In some embodiments, depending on use, deposits form on, or within, the portable generator. In such embodiments, the portable generator optionally comprises at least one deposit removing apparatus optionally comprising a scraper and/or a shaft comprising break-away segments.
In a preferred embodiment, the portable generator comprising a clip for clipping the generator to an object and wherein the embodiment comprises a housing, the housing optionally comprises a clip for clipping the housing to an object.
According to a preferred embodiment of the present invention, the portable oxidant generator comprises a housing. In a preferred embodiment comprising a housing, the housing optionally comprises a tube comprising at least one cross-section selected from the group consisting of circular, ellipsoidal, and polygonal cross-sections. In tube embodiments, the tube preferably comprises a length between approximately 3 cm and approximately 60 cm and preferably comprises a width between approximately 0.5 cm and approximately 30 cm. In several preferred embodiments, described herein, embodiments comprising a tube are referred to generally as xe2x80x9cpenxe2x80x9d embodiments of the present invention. Alternatively, the housing comprises a different shape, such as, but not limited to, a xe2x80x9ccapxe2x80x9d or xe2x80x9clidxe2x80x9d shape suitable for opening, closing and/or sealing a container; thereby the apparatus is optionally capable performing a cap or lid function in addition to oxidant generation. In a preferred embodiment, a cap-shaped oxidant generator optionally comprises at least one set of threads and/or at least one aperture for insertion of a drinking utensil, such as, but not limited to, a straw. Of course, other cap or lid functions are within the scope of the present invention including those that do not rely on threads for attaching to and/or opening, closing and/or sealing a container, for example, but not limited to, snap closure mechanisms. Alternatively, the oxidant generating apparatus resides within and/or on a surface of a container, such as, within a canteen and/or attached to a side of canteen (e.g., inner and/or outer surface).
The present invention also comprises an inventive method for treating a substance using an oxidant generator. In a preferred embodiment, the method comprises the following steps: creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte; and releasing the products onto or into a substance for treating the substance. In a preferred embodiment, the step of releasing the products onto a substance for treating comprises releasing oxidants to a liquid (fluid) and/or other substance. Accordingly, the step of releasing the products to a substance for treating optionally comprises releasing the oxidants to a substance for decontaminating the substance.
In general, generation of oxidants also results in the generation of reductants, or reducing agents. In some instances, reducing agents comprise gas, such as, but not limited to, hydrogen gas. According to a preferred embodiment, at least some of the reducing agents comprising gas are optionally vented from the oxidant generator. It is understood that the oxidant generator of the present invention preferably comprises a generator that generates both oxidants (e.g., oxidizing agents) and reductants (e.g., reducing agents).
According to a preferred embodiment of the inventive method, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products by passing water through a porous electrolyte chamber to be collected in the cell. In a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products by passing an electrical charge to an electrolyte, preferably, the electrical charge passes to the electrolyte through an anode and/or cathode. In a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products by measuring the total dissolved solids of the substance. In a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products by pressing/pushing the end of the electrolytic cell comprising a self-sealing electrolyte storage compartment when electrolytic cell is inserted into the substance. In a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products by generating an electric current in an apparatus comprising a configuration selected from the group consisting of tube configurations and cap configurations.
In a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte optionally comprises creating oxidants by: generating an electrical charge in an electrolytic cell comprising at least two electrodes; and/or generating an electrical charge from an anode comprising at least one catalyst wherein the anode and/or cathode optionally comprise titanium and/or optionally comprise a metal oxide coating, such as, but not limited to, ruthenium oxide.
In a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products by generating an electrical charge from an anode comprising at least one metal selected from the group consisting of the Group VIIIB elements in the Periodic Table of the Elements and compounds thereof. According to a preferred embodiment, the step of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte comprises creating oxidation/reduction products in a reservoir.
Preferred embodiments of the present invention comprise an apparatus to treat a substance, the apparatus comprising a portable electrolytic cell for generating oxidation/reduction products, the products to be subsequently added to the substance. The apparatus preferably comprises a hand-holdable configuration. Preferably, the electrolytic cell comprises a plurality of plates, more preferably an anode and a cathode. Preferably the anode comprises a catalytic material, more preferably a titanium substrate preferably with an oxide coating, more preferably at least one metal selected from the group VIII elements of the Periodic Table of the Elements, and most preferably wherein the oxide coating comprises ruthenium, for example, ruthenium oxide.
In a preferred embodiment of the present invention, the cathode is disposed within the anode, alternatively where the anode is disposed adjacent to the cathode and preferably comprises an outer housing for the anode, preferably wherein at least one of the anode or cathode comprises a metallic, plastic, ceramic, silicone, or a non-conducting material. A preferred embodiment also preferably comprises a pocket clip for attachment to the user""s pocket. The electrolytic cell preferably comprises a delivery mechanism for adding oxidation/reduction products to the substance, and preferably comprises a power source comprising an electrical, electromechanical, or chemical generator. The power source preferably additionally comprises a generator to convert mechanical energy to electrical energy.
In a preferred embodiment of the present invention the apparatus comprises a reservoir, preferably a salt reservoir, and more preferably a refillable or disposable reservoir. Preferably, the chamber comprises a reservoir. A preferred embodiment further comprises an electrolyte storage compartment comprising a self-sealing cap. The cap comprises an elastomer or a mechanical check valve.
A preferred embodiment of the present invention further comprises a deposit-removing apparatus, preferably a scraper and/or a shaft comprising breakaway segments. The apparatus also preferably comprises a circuit for measuring total dissolved solids (TDS) in the substance to be treated, preferably an electrical circuit included in an integral circuit, and preferably further comprises a visually readable, audible, or tactile indicator for completion of electric charge in the substance, most preferably a vibratory indicator. The apparatus preferably additionally comprises a temperature measuring device.
Additionally, in a preferred embodiment, the present invention comprises a method for measuring chlorine, for example, residual chlorine in treated water, comprising an oxidation reduction potential (ORP) apparatus. In a preferred embodiment, the present invention comprises a pH measurement apparatus that optionally provides a signal for use in adjusting the ORP apparatus for variations in pH, for example, variations in treated water pH.
The present invention is also a method for treating a substance using an oxidant generator comprising the steps of creating oxidation/reduction products in a portable electrolytic cell for holding an electrolyte, and releasing the products onto a substance for treating. Preferably, the oxidants are released onto a fluid, and more preferably the oxidants are released for decontaminating. The oxidants are preferably created by passing water through a porous salt chamber to be collected in the cell, preferably by passing an electric current through an electrolyte, and more preferably by generating an electric current from an anode to a cathode, and alternatively in an electrolytic cell comprising a plurality of plates. Preferably the anode comprises a catalytic material, preferably a titanium substrate. The anode preferably further comprises an oxide coating, and preferably comprises at least one metal selected from the Group VIII materials in the Periodic Table of the Elements, and more preferably comprises ruthenium oxide. In a preferred embodiment of the present invention, the oxidation/reduction products are created in a reservoir.
Broadly, it is the object of the present invention to provide an improved oxidant generator.
It is a further object of the present invention to provide an oxidant generator that may be carried conveniently by a single person and utilized to sterilize small quantities of drinking water.
A primary advantage of the present invention is the small size and light weight of the apparatus.
Another advantage of the present invention is the ability to measure total dissolved solids in the sample with the same apparatus to treat the water.
Yet another advantage of the present invention is the ability to measure the oxidation reduction potential (ORP) of a substance, for example, but not limited to, treated water.
Yet another advantage of the present invention is the ability to treat a larger volume of water using a portable apparatus.
A further advantage of the present invention is the use of a safe-to-produce solution to disinfect a water supply.
A yet further advantage of the present invention is the ability to provide a hand-holdable and/or portable treatment apparatus comprising, for example, a pen-like and/or container cap configuration.
Other objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.